Patent GB-1496021-A (GB)
Title: Underwater connection apparatus
IPC: E21B43/013
Filed: 1975-02-17
Abstract: 1496021 Wells &c VETCO OFFSHORE INDUSTRIES INC 17 Feb 1975 6692/75 Heading E1F [Also in Division F2] A storage flowline S from a barge L is landed at a wellhead A and connected to a christmas tree flowline F by wireline apparatus which moves the storage flowline S into partial alignment with the tree flowline F and by remotely operated power means which move the storage flowline S into complete alignment with the tree flowline F so that they can be connected together. As described a guide structure G (Fig. 1) including guide posts 11 and guide lines 12 extending to a vessel V (Fig. 11) is landed on the well H. An alignment assembly B (Fig. 5) is then lowered down two of the guidelines 12 and is landed on, and latched to, the base of the guide structure G. The alignment assembly B has an alignment channel 17. A christmas tree T having flowlines F terminating in a flange 22 is then run along the guidelines 12 into position on the guide structure G and alignment assembly B, the tree T being positioned so that the tree flowline flange 22 is inserted into the alignment channel 17. A flowline pulling tool P (Figs. 5, 10) is then landed on the alignment assembly B and is connected thereto by latch 69. The pulling tool P includes a wireline W which extends from the vessel V, around a pulley system, through a funnel 65a to a landing assembly 41 to which the storage flowline flange 40 is releasably connected. The landing assembly 41 also carries a testing flange 50 having differently shaped pins (not shown) for each flowline S-1, S-2, S-3. A lead plug is pumped down each flowline as far as it will go and is then pumped back to the surface. If the lead plug has received an impression from the corresponding pin then the flowline is clear. The storage flowline S is pulled down from the barge L by the wireline W until a probe 43 enters the funnel 65, the storage flowline S then being in partial alignment with the tree flowline F. Hydraulic cylinders 76 (Fig. 5) are then operated to pull the landing cylinder 42f (Fig. 10) into the funnel 45a and lock the landing assembly 41 thereto, a lug 43f on probe 43 engaging a cam surface (not shown) in the funnel 65a to orientate the landing assembly 41 so that the storage flowline flange 40 is vertical. Cylinders 74 (Fig. 5) are then operated to tilt the funnel 65 so that the storage flowline flange 40 is inserted into the alignment channel 17 in which position it is in complete alignment with the tree flowline flange. A cylinder (not shown) is then operated to release the flange 40 from the landing assembly 41 which is then withdrawn. The flange 40 is held in the alignment channel 17 by horizontal and vertical spring loaded detents 45 (Fig. 10) engaging T-shaped grooves 17d in the channel side plates 17a, 17b. The flowlines F, S are connected together by operating cylinder 27b (Fig. 24) on the tree flowline flange 22. The cylinder 27b moves side plates 26 downwardly, the side plates 26 having cams 26d, 26e which engage lugs 40g, 40h on the storage flowline flange 40 to move the two flanges 22, 40 into engagement with each other. The flange 22 carries on its front surface a plate (not shown) having seals to provide a fluid tight connection between the two flanges 22 and 40. The various hydraulic cylinders 74, 76, 27b, &c, are operated remotely from the surface vessel V, being connected thereto by hydraulic lines (not shown).